4x + y = 8 6y- 9y = 12 which of the options represents the resulting equation after an equivalent expression for y is substituted into the second equation? 4x + 4x - 8 = 8 6(4x - 8) - 9y = 12 6x - 9(-4x + 8) = 12

6x - 9(-4x + 8) = 12

Solving the first eqution for y, you have

... y = -4x +8

Substituting that into the equation

... 6x -9y = 12

you have ...

... 6x -9(-4x +8) = 12 . . . . . . . matches the 3rd choice.

Comment on the question

The given equation is 6y -9y = 12, something entirely different from 6x -9y = 12. None of the answer choices apply to the equations given in your problem statement.

f(x) = - 2/3x + 5; f(5/2)

substitute 5/2 in for x:

f(5/2) = -2/3(5/2) + 5

simplify the right side:

f(5/2) = -5/3 + 5

f(5/2) = 10/3

answer:

f(5/2) = 10/3

i hope this you!